Well I found out something else recently: why record labels don’t add digital booklets to older releases. The answer is interesting; it’s because they can’t. Apple won’t let them. If a label has uploaded an album to the iTunes Store and wants to add a digital booklet later, the only way they can do this is to delete the original, and create a new album listing with a new SKU. And if they do this, then purchasers will no longer be able to re-download music listed under the old SKU.

It’s kind of foolish; it should be drop-dead simple to add something to an album on the iTunes Store, but Apple’s system is so rigid that it’s impossible. So if you wonder why your favorite label hasn’t added digital booklets to older releases, you now know why.

A number of people have found that iTunes Match sometimes matches incorrect tracks; not that the songs are wrong, but that the versions might be wrong. This seems to happen especially with music that has been remastered. iTunes may match either an original or remastered track, and the user who matched the track may have tho one that iTunes doesn’t have. This can be a problem, if, say, you prefer an original album over a remastered version, or vice versa.

But I today I found, for the first time, a bad track coming from iTunes Match, one with an audible problem. It’s one of an excellent set of Bill Evans recordings, The Last Waltz, from the summer of 1980, just before his death, made at the Keystone Korner; the song is Your Story, While iTunes matched these tracks, I was listening to some of this music today, and found a bad track. There’s a gap of about a half-second at one point in the track. Looking at it with Rogue Amoeba’s Fission, you can clearly see the missing chunk of music:

If this happens, you’re basically screwed. Who can you complain to? Contact the iTunes Store? I doubt anything will happen. The only way to have a good copy of the track is to take your original and make sure it stays in your library; if you ever have to download it again, you’ll get the track with the gap. It’s worth noting that this track is not available on the iTunes Store. This makes me wonder exactly how they match such tracks; do they match them to tracks that other people have uploaded?

I don’t expect this will happen a lot, but the fact that it happens at all shows the weakness of this system. iTunes Match clearly needs an option for tracks that you don’t want matched, ones that you want uploaded, because the matched version may not be the same as yours.

Has anyone else found matched tracks that have similar problems?

(As an aside: if you like Bill Evans, there are two box sets of this run at the Keystone Korner, in San Francisco, between August 31 and September 8, 1980. The Last Waltz is music from the first sets, and Consecration has tracks from the second sets. Just a week before his death, Evans was playing some of his finest performances. These two box sets, together with Turn Out the Stars, recorded at the Village Vanguard in June, 1980, comprise 22 discs of astounding piano music.)

Update: my son came across a bad track today. It’s a match of Philip Glass’s Witchita Vortex Sutra, from the Minimal Piano Collection box set. There are clicks throughout the track, with one big dropout at 4:25:

I recently pointed out that the Apple Lossless codec has gone open source, meaning that this lossless codec can now be freely used in both hardware and software. The Apple Lossless codec (also known as ALAC) is similar to FLAC, and offers the same advantages. When you compress files in a lossless format, you lose absolutely none of the original data. Just as when you compress a text file using zip compression, decompressing returns all the original letters and characters, lossless music compression provides the full fidelity of the original audio you compressed.

It’s interesting to look at the sizes of files compressed in Apple Lossless format. (These file sizes are similar for other lossless formats, such as FLAC, SHN and APE.) I took a handful of CDs, and ripped some tracks to show how the amount of compression can vary.

When comparing file sizes, the easiest way is to look at the bit rate that displays in iTunes. (Comparing file size is more difficult, as the different files used would have to be the same length for this to be valid.) This is an average bit rate, but it gives an idea as to the amount of compression that was achieved. Different types of music, notably with different instruments, result in compression rates that vary widely. Compare the bit rates below to the bit rate of uncompressed music on a CD, which is 1411 kbps.

Here are some examples:

A solo harpsichord work by Johann Sebastian Bach: 902 kbps

A solo piano work by Johann Sebastian Bach: 554 kbps

A movement of a string quartet by Ludwig van Beethoven: 565 kbps

A choral work by Johann Sebastian Bach: 690 kbps

A piece for jazz piano trio by the Brad Mehldau Trio: 687 kbps

A live recording of a song by the Grateful Dead: 796 kbps

An excerpt from Steve Reich’s Music for 18 Musicians: 597 kbps

A movement of a symphony by Franz Schubert: 645 kbps

A song for male voice and piano by Robert Schumann: 446 kbps

Again, these figures are in no way absolute, and for each piece of music, the resulting level of compression could be different if the tempo, volume or instrumentation varied. But what they do show is that some types of music – notably solo harpsichord, which has a high level of harmonics at high frequencies – compress less well than, say, solo piano or voice and piano. The range of compression for these examples is from 36% to 68%, with the majority of the examples clustering around the 50% level.

Note that I haven’t tested much rock music, and especially not much recently recorded rock or popular music. With many recent recordings having high volume and using compression (not the type that reduces data size, but the kind that reduces the dynamic range of music), file sizes can be much larger. If you listen to recent recordings of such music, you’ve probably noticed that they are often very loud, compared with, say, recordings from a couple of decades ago, and these will result in higher overall bit rates when using lossless compression.

A report from CNN suggests that Apple is moving iTunes toward 24-bit music files. What this means is that, instead of using 16-bit CD-quality files (AIFF or WAV files) to convert to the AAC format that iTunes sells, they would use masters which are recorded at 24 bits. But this makes little sense, if Apple were to simply continue to sell files in compressed AAC format.

24-bit files offer only one major improvement over 16-bit files: an increase in dynamic range, or the difference between the softest and loudest parts of music. This difference would, however, be lost if the files were compressed. So the only way that Apple could offer improved quality in the music files they sell is if there were to provide them in Apple Lossless format.

Apple Lossless format does support 24-bit audio, but given the quality of digital-analog converters (DACs) in most computers – Macs included – listeners would not notice much of a difference. While many audiophiles swear by lossless formats, the only possibility to hear a difference between them and lossy formats at decent bit rates is with very expensive audio equipment. (And even then, the placebo effect certainly comes into play.) Users who have an external DAC that supports 24-bit files might see a small improvement, at least as far as the dynamic range is concerned, but other than that, there aren’t many advantages to selling this format for use on computers and iPods. (Some may find this forum post and thread interesting for a heated discussion of the differences between 16- and 24-bit audio.)

The differences between 16-bit and 24-bit files can be somewhat complex, and 24-bit files can take up as much as three times as much disk space as 16-bit files. While Apple may want to get into the “studio master” market – a number of classical labels sell files in 24-bit / 96 khz format – it is likely that only a very small percentage of users would buy such files. The audiophile market is a niche market to start with, and files in this type of format won’t attract many listeners.

This said, if Apple were to offer files in Apple Lossless format as on option, this could attract a group of listeners who refuse to buy compressed music. With file sizes (at 16 bits) of a bit less than twice the size of Apple’s current 256 kbps files, they don’t represent a huge leap in bandwidth and storage space requirements. When burned to CD – if anyone still does that – they reproduce the exact data that was on the original CD. And, since they require more space, it’s possible that users would buy larger capacity iPods.

The trend in music downloads, at least for classical music, is toward lossless files (generally in FLAC format). Apple is a laggard in this respect, despite the fact that they offer their own lossless format. It’s obvious that Apple will make this step one day, but going to 24-bit would be only for a limited number of tracks, and most likely only for those tracks that would attract audiophiles. Lady Gaga in 24 bits still sounds the same.

One more thing: the Apple Lossless format supports 5.1 audio tracks. I’d be far more interested in surround sound than 24-bit audio. While I could only play it on my living room stereo, assuming that it could be correctly streamed through my Apple TV, this would be something that might be more popular. Though not many albums are available in 5.1 mixes yet.

Is iTunes Bloated? That’s a question I asked on this site back in June. I got some answers, responded to them, but I wasn’t convinced by much of what people were saying about iTunes bloat.

I’ve written an article for TidBITs called Is iTunes Bloated?, examining some of these points, rebutting many of them, and pointing out where iTunes could be changed, and where it can’t be. I’m sure many people will disagree with me on this, because this seems to be a question where people have entrenched ideas.

I admit that I know iTunes pretty well, and am not daunted by its many features. I’ve just written about them in Take Control of iTunes 10: The FAQ, for those who want to learn more about using the program.

I have a lot of music: my iTunes library currently contains about 40,000 tracks. I buy a lot of CDs, buy music from the iTunes Store, listen to audiobooks, and download podcasts. This library increases in size as I rip more music, and it has gotten to the point where performance is very, very poor.

I have a Mac Pro (with four cores) that has 4 GB RAM and plenty of hard disk space, so I’m clearly near the high end of potential performance. But as iTunes has progressed, it has not improved its performance; whenever I make any changes in my library (change tags, add tracks, download podcasts), it takes about 5 seconds for the program to become responsive. I get a spinning beach-ball and the program simply pauses (though, to be fair, in most cases it continues playing music if I’m listening to something with iTunes).

I first saw performance problems when ripping CDs, a bit more than a year ago when I bought my Mac Pro. I had hoped it would be faster than my previous computer, a G5 iMac, but it was only marginally more rapid. So I bought a second optical drive: a 52x CD-only drive (the Mac Pro has a superdrive which reads CDs slower than that). This improved ripping speeds a bit, but I finally got fast rips when I created a second iTunes library just for ripping – this proves that the problem is the library size, not the program itself, my optical drive, or my Mac. I can get up to 40x rips now, at the ends of CDs, compared to a max of around 22x with the superdrive.

My iTunes Library file is large: 68 MB. My guess is that iTunes, when working with a file this size, has to write the file anew each time there is a change, and that this is what slows down the program. I see 5-second delays when I simply download a podcast (at the end of the download, when, I assume, the file’s information is written to the library file), or when I uncheck tracks from smart playlists that contain only checked tracks. Any operation that leads to changes in the library file seem to cause the program to hang for five seconds.

I don’t see any solution, other than Apple improving the performance of iTunes and its library files. As people use iTunes more, they are likely to increase the number of tracks they have, and their performance will degrade, so more users will be seeing these problems, especially with slower computers.

At each release of an iTunes update, I hope that Apple will resolve this problem. Alas, after yet another update today (7.7.1) it seems to be even worse when ripping CDs.

UPDATE: When Apple release iTunes 8, responsiveness improved greatly, but there are still lags when tagging files and when importing. It is better, but it’s still far from perfect.

Are you a classical music fan? Then this new article is a must-read for you. I’ve written the first of a short series for Playlist, the website of Playlist Magazine. Find out about compressing and importing classical music, joining tracks and more here.